Emergency antenna



June 29, 1937. w. A. HAMILTON EMERGENCY ANTENNA Filed Jan. 30, 1937 2 Sheets-Sheet 1 INVENTOR. Wa/fer 14. Hamf/fon ATTORNEYS,

June 29, 1937. w. A. HAMILTON EMERGENCY ANTENNA INVENTOR. W4 lfer ,4, Ham/Hon 2 Sheets-Sheet 2 will! ljIl Filed Jan. 50, 1951 ATTORNEYS,

Pate nt ecl June 29, 1937 PATENT OFFICE EMERGENCY ANTENNA Walter A. Hamilton, Kansas City, Mo., assignor to Transcontinental & Western Air, Inc., Kansas City, Mo., a corporation Application January a, 1937, Serial No. 123,220 9 Claims. (01. 250-33) This invention relates generally to radio apparatus for airplanes and specifically to emergency antennaassemblies designed for use as equipment auxiliary to the regular trailing antenna now commonly employed.

One of the important aims of the present invention is to provide an emergency antenna assembly that may be carried adjacent to an opening formed, in the airplane body so that'upon failure of the regular trailing antenna, or due to the loss thereof, another trailing antenna might be quickly disposed in the operative position by the pilot or other attendant.

. A further aim of this invention is the provision lfiof an emergency antenna for airplanes, which includes as a part thereof, a projectable coil antenna. cable, manually releasable mechanism I for forcibly expelling the said cable, and a switch which simultaneously acts to electrically connect the antenna cable with the radio receiving or sending apparatus that constitutes a part of the airplane equipment.

An even further object of this invention is to provide an emergency antenna assembly of. the g5 aforementioned character that is simple in construction, effective in operation, light and. positive in performance.

Other objects of, the invention are. also contemplated and will appear during the course of the following specification, referring to the, ac-

companying drawings, wherein:

Figure 1 is a fragmentary, perspective view of the tail portion of an airplane equipped with an emergency antenna embodying the present invention. i

Fig. 2is an enlarged, longitudinal, central,

sectional View through the emergency antenna assembly, showing the sameentirely removed from association with the airplane.

4-0 Fig. 3 is a sectional View, taken along line IIIIII of Fig. 2.

Fig. 4 is a cross section through the assembly, taken along line IV-IV of Fig. 2, looking in the direction of the arrows.

i Fig. 5 is a similar cross sectional view, taken along line V-V of Fig. 2, looking in the direction of the arrows. p

Fig. 6 is an enlarged, longitudinal, central section through theantenna cable fixture per se.

Fig. 7 is, a cross sectional view through the fixture, taken on line VIIVII of Fig. 6, and

Fig. 8 is a fragmentary, side elevational'view of a portion of the tube forming a part of the fixture.

5 5 The tail portion ID of an airplane of present bore 68 drilled through the closed end {of tube commercial type is usually equipped with a tail light l2 and a trailing antenna socket [4. When installing an emergency antenna assembly -embodying the present invention, tail piece l0 should be provided with an opening It of a size sufiicient: to permit the passage of the hereinafter more fully described coiled antenna cable l8. Opening i6 is disposed so that antenna cable I8 is traveling in a direction opposite to the movement of the airplane at the time of ex- 10 pulsion.

Figures 2 to 8 inclusive illustrate one commercially satisfactory embodiment of the features of this invention. A base casting 20, which may be secured to and form a part of the end of the 15 airplane housing, is provided with an opening 22 and cavity 24 that contribute in providing supports for regular trailing antenna socket Hi and parts of tail light [2 respectively. The opening i6 is formed in base 29, and a groove 28 cut into the inner annular side provided by opening [6, receives a frangible cover 30 and retaining spring 32. Retaining spring 32 is ringshaped and resilient, so that cover 36 may be quickly replaced. A barrel 34 extends inwardly from base 20, with its longitudinal axis on the 25 center of, opening 26, and is suitably secured to an annular flange 36, integral with base 20. The innermost end of barrel 34 is closed by a retainer 38, and a guide M], of insulating material, is slidably carried within barrel 34. A central opening 42, formed in guide '40, receives fixture l l, and an expulsion spring 46 is positioned between retainer 38 and guide 48.

The coiled antenna cable iilis, in the instance shown, wound upon a spool 48 which lies in close proximity to the outer end of barrel 34 and adjacent to cover 30. One end of antenna cable I!) is secured to fixture 44 in an unique manner. The tube 5i forming a part of fixture 44, has at least one slot 52 formed through the wall thereof, which terminates in a hook-shaped opening 54 that receives one end of cable l8. Collars 56 circumscribe tube 50 to overlie cable I8.

Fixture 44 is mounted upon guide it, as illustrated in Fig. 2. One collar 56 forms a shoulder to lie against the outer face of guide M, while nut 58 may be tightened against the inner face of guide 40 merely by turning the same upon its threaded support forming a part of tube 5%. A connecting rodBD has a head 62 on the inner end thereof, and a spring (it lies between. head 62 and shoulder 66 that circumscribes that portion of connecting rod 69 which passes through 50. One end of wire Ill is suitably secured to the outer end of connecting rod 60, while the other end thereof is joined to a switch clip 12.

A switch mounting 14, having Vertical guides 16, is secured to barrel 34 by a pair of strap anchors 18. A release element 80 is slidably carried by guides and projects into barrel 34 through a slot 82. Release element 80 is operably joined to one end of bell crank lever 84, while the other end thereof has connected thereto a clevis 86 and push rod release 88. Bell crank lever 84 is pivotally supported by switch mounting 14 between ears 90 by pin 92. Switch blade 94 is rigid to bell crank lever 84 and travels from the position shown in full lines to the position shown in dotted lines of Fig; 2."

"Another clip 96, similar to clip 12, forms a.

part of the switch. These two clips "and 96 sit upon a switch block 98, that in turn is carried by switch mounting 14. This clip 96 is electrically connected to the radio apparatus of the airplane.

' Push rod release 88 has one end pivotally joined Operation Under normal conditions, the airplane equipped with an emergency antenna assembly as hereinbefore described, will have the regular trailing antenna extending from socket l4. 'The parts of the said assembly will be in the relation shown.

especially in Fig. 2. Upon the loss of the regular antenna, the pilot will want to immediately bring into play an emergency antenna, and may do so merely by manipulating connections to clevis 86. Such manipulation will withdraw release element 80 from'in front of guide 40 so that expulsion spring 46 may quickly and positively move guide 40 and fixture 4B longitudinally along barrel 34 and against spool 48. This quick action will force the spool of coiled antenna cable through cover and the cable will unwind so that its free end will trail behind the airplane. Spool 48 is lost. 7 Wire llifby virtue of its connection with one end of cable l8 and clip 12, will be joined to the radio apparatus of the airship when switch blade '94 is'drawn downinto clips 12 and 96. If the trailing cable I8 is inclined to jerk wire 10, spring 64 will absorb the shock incident to such jerking and preclude injury to connecting wire 10. 7 From the foregoing it will become clear toone [skilled in the art that the emergency'antenna assembly is effective, efiicient and desirable. The use of a frangible cover and other associated parts insures that the coil antenna cable l8 will be protected from the elements until the instant it is brought into play. 7

While one preferred embodiment of the invention has been'illustrated and described, itis decable within the housing adjacent to the opening;

a and manually releasable mechanism for forcibly projecting the said coiled cable through said opening.

2. In an airplane having a body provided with an opening, the combination of a. coiled antenna cable within the housing adjacent to the opening; and manually releasable mechanism for forcibly projecting the said coiled cable through said opening, said antenna cable having one end an chored within the housing whereby upon projection the cable becomes a trailing antenna.

3. In an airplane having a body provided with an opening, the combination of a coiled antenna cable within the housing adjacent to the opening; and manually releasable mechanism for forcibly projecting the said coiled cable through said opening, said opening having a frangible ,cover thereover which is broken by the coiled antenna cable as the latter is forced through the opening. 1

4. In an airplane having a body provided with an opening through the tail portion thereof and radio apparatus therein, the combination of a coiled antenna cable within the housing adjacent to the opening; a switch; and manually releasable mechanism for forcibly projecting the said coiled antenna cable through said opening, said switch having a clip in connection with the radio apparatus of the airplane and another clip in connection with said coiled antenna cable, said releasable mechanism having a blade for connecting the clips'as the coiled antenna is projected through the opening whereby to operably interconnect the antenna cable and radio apparatus when the former becomes a trailing antenna.

5. An emergency antenna assembly of the character described comprising a barrel; a coiled antenna cable within the barrel; a frangible cover closing one end of the barrel; means for exerting force upon the coil antenna cable to project the same through the cover; and mechanism for releasably holding the said means inoperative.

6.- An emergency antenna assembly of the character described comprising a barrel; a coiled antenna cable within the barrel; a spring for projecting the coiled antenna cable from the barrel; and mechanism for releasably holding the spring under tension and in'inoperative condition with respect to the said cable. '7. An emergency antenna assembly of the character described comprising a barrel; a coiled antenna cable within the barrel; a switch mounted on the barrel having a membermovable to open and close the same; and mechanism, including said movable switch member, for releasably holding the spring under tension and in inoperative conditionwith respect to the said cable, said movable switch member being in the switchclosing position when the mechanism is in place to release the spring.

8. An emergency antenna assembly of the character described comprising a barrel; a coiled antenna cable within the barrel; a switch mounted on the barrel having a member movable to open and close the same; and mechanism, including said movable switch member, for releasably holding the spring under tension and in inoperative 7 condition with respect to the said cable, said movable switch member being in the switch-closing position when the mechanism is in place to release the springsaid antenna cable having a fixture at one end for anchoring that end to the assembly. j

9. An emergency antenna assembly of the character described comprising a barrel; a coiled antenna cable within the barrel; a switch mounted on the barrel having a member movable to open and close the same; and mechanism,

including said movable switch member, for re Ieasably holding the spring under tension and in inoperative condition with respect to the said cable, said movable switch member being in the switch-closing position when the mechanism is in WALTER A. HAMILTON. 

